Electric furnace.



A.`E. GREEN-E. ELECTRIC FURNACE. APPUCATION man 061.12, 1911. RENEwEDAus.9.1918.

1,297, 14:9. Patented Mar. 11, 1919 UNITED sTATEs PATENT oEEicE.:

yALBERT E. GREENEQOF SEATTLE, WASHINGTON.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented Mar.. 1i, 1919.

Application led October 12, 1917,"Se1ia1 No. 196.318. Renewed August 9,1918.-' -Seria11\To. 249,2O0- K strength and greater capacityinproportion to its weight than the. shells of electric furnacesheretofore made. and whose llnmg shall he so disposed within said'shellthat. any portion of it cannot be loosened anddisplaced by necessarymovementsA of the furnace to different angular positions in theVoperations of lcharging said furnace and discharging molten metaltherefrom'.

Another object of my invention is to provide a furnace the internalsurface of whose lining shall be of`such contour that a horizontalsection of tlie interior space of said furnace shall be greatest inlarea at .the normal-surface level of the mass of metal contained thereinat which level will be the most intense heat of the electricarcs duringthe. operation of said furnace.

' still further object of my invention is to provide an electric furnacewhich shall embody means which shall be adapted to be operated to imparta rotative movementto.

its shell to facilitate the ope at-ion of extracting portious,vor all,of its contents therefrom. or which shall embody modified means forimparting a rocking movement to said shell to facilitate the operationof extracting a desired portion of the molten contents thereof.

I accomplish these objectsby devices illus-v trated in l theaccompanying drawings, wherein- Figure 1 isl a view in rearward sideele--l vation of one form of an electric furnace embodying my invention;

Fig. 2 is a view of the samel in vertical section on broken line 2. 2 ofFig. l;

Fig. 3 is a view of the same in horizontal 'section on broken line 3, 3of Fig. Y1;

Fig, 1t is a view, on a reduced scale, in rearward side elevation of amodified form `of a furnace embodying my invention; and

Fig. 5 is a view of the same in end elevation as 1t appears when tiltedin the operation of discharging its molten contents.

Referring to Figs. 1,12 and 3 of the drawings, throughout 'which'drawings -like ref- The outwardly bulging concavo-convexl vend walls 7and '8 are not only of the strongest form but such form gives thegreatest area ina horizontal section of the furnace chamber at a point'where it is most desired.'and is adapted to the arching of the endwalls. A

The cylindrically formed furnace shell is disposed with its axis in ahorizontal line, and fastened to the exterior surface of its lower halfportion are two'roller-engaging members 1l and 12. of T-shapedcross-section, which extend circumferentially in arcs of circles on saidexterior surfaces of said lower half portion. the roller-engaging member11 being spaced a short distance from the end wal-l 7 and theroller-engaging member '12 being spaced-a like distance from the ,endwalll S, as shown in Figs.I 1

I aind 2.

The. furance is so disposed that the rollerlengaging 'members l1 and 12operatively 'rest upon and engage with a plurality of rollers, asrollers 13, thereby to support said furnace and adapt it to be'rotatively moved in the operation of tilting said furnace todischarge'its contents, said rollers 13 being pivotallyv mounted insuitably supported bearings not shown.

.Fastened to the Youter surface of thecylindrical wall 6 in \a positionspaced from and'parallel with the inner side of the rollerengagingmember 11, is a. curved toothed rack 14 whose teeth operatively engagewith the teeth of a pinion 15 that is fastened on i mounted in suitablysupported bearings not shown, to which shaft 16 rotary motion may becommunicated by suitable means, not

shown, thereby rotatively to move and tiltA thev furnace shell in theoperation of discharging the contents thereof.

A segment of the upper portion of the cylindrical wall 6 is cut away toform an opening that extends lengthwise between the flanges 9 and 1() ofthe outwardly bulging dished end walls 7 and 3, and adjacent to saidopening the opposite.longitudinal edge portions of said cylindrical wall6 are re"- inforced by liars 17, of angular form in cross-section, whichpresent flat surfaces that are disposed in a horizontal plane, uponwhich flat surfaces is removably disposed a .roof that serves to coversaid opening, said roof comprising a rectangular frame 18 of channeliron within which is securely fixed an arch 19 foi'ined of fire brick orother refractory material:

Fastenedto the outer side of the lower portion of each of the oppositelonger-sides of the .frame 18 is a bar 20 of angle iron whose under sidesui'face normally rests on the flat surface of the adjacent bar 17.

The inner surfaces of the cylindrical wall 6 and the concave surfaces ofthe dislied end walls 7 and S are provided with linings (as linings 21and 22, respectively) made of refractory brick which as shown are soformed and relatively disposed that no portions of said linings can beloosened and displaced bytilting movements of the furnace shell. v

Extending through the lining 21 and-cylindrical wall 6 in the rearwardside thereof is an opening 23 which is closed by a remov- .able door 24that is normally supported by a bar 25 that is fastened in a horizontalposition to the cylindrical wall 6 adjacent to the lower edge of saidopening 23. Disposed substantially opposite th'eopening 23 is an outletopening 26 that extends through the lining 21 and cylindrical wall 6with which opening is associa-ted a spout 27 which serves to conductvmolten metal from the interior of the furnacein response to the tiltinof said furnace by rotative movements tiere-of, which rota-tive move-.ments may be effected in an obvious-manner by rotating the shaft 16..The top opening of the furnace may be used for charging when desired bylifting off the roof.

Adjustably and slidably disposed to eX.-

' tend downwardlythrough. the removable arched roof 19v into 'theinterior of the furnace is an electrode 28, of well known form, which ismaintained-iii -a well known ina-nner in Vits adjusted position byl alcable 29 and pulley 30. v

Extending downwardly through the; lining 21 and cylindrical wall 6, withits axis-inline with the airis of the electrode 28, is another electrode31 whose upper end surface registers with the linner surface of thelining 21, said electrode 31 preferably being made of metal suitablywater cooled.

The electrodes 28 and 31 are adapted to be connectedwith a source ofelectricity in a well known manner not shown whereby an electric are`may be formed between thebottom end of said electrode 28 vand the topsurface of any metal that maybe incontactwith the top end surfaceof theelectrode 31, the heat of which electric arc may melt said metal, whichmetal when melted, may be discharged in required quantities through thespout 27 by turning the shaft 16 thereby to tilt the furnace by arotative movement thereof.

1n Figs. 4 and '5 l have. shown a furnace similar to the furnace ofFigs. 1, 2 and 3 eX- cept that the cylindrical portion of the shell soYis of greater length so as to provide space inside (the furnace chamberfor the use of a plurality vof electrodes, three in the furnace shownand that it embodies an improved means of tilting. This furnace isdesigned for large charges. It is adapted for three phase current toenter through the three top electrodes 40, 41 and 42 which may-be adjusted and regulated in any well known m'anner not shown. In the bottomis shown a with water. The heating'may be carried on in any well knownmanner, as between the top electrodes and the charge, either with orwithout the use of the bottom electrode.

. bottom electrode 43 made of metal and cooled Two doors are shown onthe rearward side of the furnace 32 and 33. The furnace'is adapted to betilted to discharge its contents 'by means comprising rail-tracks 34 and35 upon which are operatively disposed railenvacinv membersl 36 and 37res ectivelv c es A a: a a

4(which correspond to the roller-engaging members 11 and 12.0f Figs.land 2) whereby a rockingmovement may be' imparted to the furnace totilt it in response to force exerted on a. connecting rodA 38 in a.manner not shown, one end of which connectingrod 33 is articulated to abracket 39 fastened to the rearward side of the furnace shell. This typeof tilting mechanism has the ad vantage of silnplicity of constructionAtogether with the fact that the movement of the end of the spout can bekept almost up and down so vthat little movement or no movement of theladle is necessary in order' space of the furnace chamber is more nearlyisa spherical in form and thus the Walls and lining of the furnacepresents less volume for the connection of heat and less ,surface forthe radiation of heat, in proportion to its capacity, than do furnacesheretofore made, whereby a. greater portion of the heat from theelectric are is usefully employed.

The construction of the furnace shell differs from those heretofore usedin that it provides room for a very thick bottom and itfurthermore,provides for the use of a brick arch roof at a. sufficientdistance from the source of heat, namely the electric arc; secondly theroof has a much longer life than in furnaces heretofore made. By reasonof the continuity of the circular flanges on the dished and flangedheads, the latter are stronger than plate heads without flangescontinuing around the top; furthermore, the dished portions of the headsgive maximum strength and also a suitable space for the most desirablecontour ofthe furnace lining in every direction.

lVhil'e I have shown the lining of the furnace as made of refractorybrick, silica brick for example, it is understood that any suitablerefractory material may lbe used and that the lining may be made bysuitably mixing the refractorie's and binding 'material and `disposingit or ramming it into place within the shell to the contour desired,either with the use of a form or without. After ramming in place it maybe dried in any well known manner. f

It is understood that the door-waysentering the furnace chamber may belined with arch brick in any suitable way to maintain the arching of thewall so as to maintain the walls in place during the rocking movementsof the furnace.

Obviously, changes in dimensions and in arrangement of parts may be madewithout departing from the novel features of my invention.

lVhat I claim is l. An electric furnace comprising a cylindrical steelshell, a dished and flanged steel head riveted to each end of saidshell, an opening in the top of the cylindrical shell, a refractorylining within the shell conforming to the inside thereof and inclosing afurnace chamber, an arched roof covering said chamber and a suitableopening for the charge or discharge of material into orfrom saidchamber,suitable electrodes for forming an' arc or arcs within saidchamber; a track adapted to support the weight of the furnace and meansof rolling the'shell over on said track to the desired degree.

Q. An electric furnace comprising a cylindrical metal shell ofhorizontal axis, an outwardly bulging metal lhead attached to each endthereof, an opening in the top of the cylindrical portion of the shell`a lining of ,refractory brick within the shell and inclosing afurnacechamber in the Wall portions of which the brick are placed inhorizontally-arched relation with each other in such manner as toprevent their dropping into the furnace chamber when in rolledoverposition, a roof covering the chamber, suitable openings into thechamber for charging and discharging, electrodes operatively disposed tomaintain an arc or arcs Within the chamber, and means of rolling thefurnaceover onva suitable track for the purpose of charging ordischarging its contents.

3. An electric furnace comprising a metal shell, said shell consistingof a cylindrical section having horizontal axis together with outwardlydished ends attached to the cylindrical section, a refractory liningwithin the shell conforming to the inner surface there of and inclosinga furnace chamber, an opening in the shell above the furnace chamber, anarched roof covering the chamber, suitable openings in the chamber Wallsfor the charging anddischarging of material', one or more electrodesentering said furnace chamber, a suitable track-engaging memberattachedto each end of the shell, said members engaging a track or railbeneath on which the track-engaging members are adapted to roll, andmeans of imparting movement to the shell whereby it may be made to rollalong the track until rotated to the desired degree.

et. An electric furnace comprisinga metal shell having a wall of theform of a hollow cylinder whose axis extends horizontally in combination.with outwardly-bulging, circular, dished end walls, said cylindricalwall .having an opening in the top for a roof" and suitable openings inthe sides for the charging and discharging of material; a lining ofrefractory material disposed within said shell Ato conform to thegeneral shape thereof; a roof of'refractory brick covering the topopening of the shellyelectrodes adjustably disposed to maintain an arcWithin the chamber formed by the refractory lining; a suitable trackbeneath said cylindrical shell wall; suitabletrackengagng membersattached to the cylindrical Wall; andA means of imparting -a rockingmovement. to the shell whereby it. may be made. to roll along the trackfor the purpose of charging or discharging its contents.

An electric furnace comprising a cylindrical metal shell, a dished andflanged metal head secured to one end 0f' said shell and a like headsecured to the other end of said shell, said shell having an opening inthe upper portion thereof` a refractory lining within said shellconforming to the inside thereof and inclosing a furnace chamber, anarched roof covering said chamber by fitting on said opening in saidshell, suitable electrodes for forming an arc or arcs Within saidchamber', and mechanism carried by said shell to provide for thecharging and discharging of material into and from said furnace chamber.

6. An electric furnace comprising a cyliiidrical metal shell on ahorizontal axis, an outwardly bulging metal head attached to each end ofsaid metal shell, a lining of refractory material Within said shell and'inclosing a furnace chamber, a removable roof for said chamber, meansfor permitting the charging and discharging of material into and fromsaid chamber, electrodes operatively disposed in said chamber to main.

furnace chamber, an .arched roof fitting an` ope-ning in said shell.above the furnace chamber, means having openings in said chamber forpermitting the charging of material into said chamber and the dischargeof refined material therefrom, one or more electrodes extending intosaid furnace chamber, and mechanism for tilting the furnaceto effectdischarge of refined material there- `8. An electric furnace comprisinga cylindrical' plate portion having a horizontal axis, two outwardly(lished plate heads re. spectively riveted to the ends ofsaidcylindrical portion to form a shell having an opening at the upper sideof said cylindrical portion between said heads, a refractory lining forthe shell composed of said cylindrical portion and said lie-ads, and acover for said opening, seid cover comprising a brick arch adapted torest on the refractory liningvof the furnace shell.

9. An electric furnace comprising a cylinF drical shell havingconcave-convex ends, a refractory lining to form a chamber havingspherical-shaped end Walls and a cylindrically-shaped bottom, and adischarge spout extending radially and laterally from said cylindricalshell With the discharge end of said spout normally in a plane extendinghorizontally through the axis of said shell a short distance abovethe-surface of the bath on the cylindrically-shaped bottom of saidchamber.

l0. An elect-ric furnace comprising a cylindrical shell havingconcavo-convex ends, arefractory lining to form cylindricallyshaped sidewalls, 'a cylindrically-shaped bottom and spherically-shaped ends, acover for an opening in said shell, and a refractory lining for saidcover forming an archshaped roof for said chamber.

ll. An electric furnace comprising a-cylindrical shell and closed ends,a refractory lining', a removable cover for an opening in said shell,and a refractory lining for said cover to form an arch-shaped roof forthechamber Within said refractory lining.

12. An elect-ric lfurnace comprising a cylindrical shell having closedends, a refractory lining forming a chamber, a flat door for a chargingopening extending into said Y chamber, andan extension from such refrac-I.means for supporting said door in closed position, and extensionsforsuch refractory lining at said charging opening to form surfacescoperating with said door to close said charging opening.

14. In an electric furnace, the combination with a cylindrical shell ofmetal having concavo-convex ends, an upper longitudinal opening, alateral charging opening, and a radial discharging opening; of arefractory lining to form cylindrically-shaped lateral Walls, a.cylindrically-shaped bottom, and spherically-shaped ends of an interiorchamber; a cover for the upper longitudinal open# ing in said shell; arefractory lining for said cover to form an arch-shaped roof for saidchamber; a door for said charging opening; a spout at said dischargingopening; an electrode extending through said cover and said arch-shapedlining into said chamber; an electrode extending through the bottom ofsaid lining; mechanism for supporting the aforesaid parts for combinedrotary movement; and mechanism for transmitting rotary movement to saidfurnace to effect discl'iarge of refined material from said chamber outof said spout.

'In Witness whereof, I hereunto subscribe my name this 1st day ofOctober A. D. 1917.

, ALBERT E. vGREENE.

.'Vlitnesses: I

GERTRUDE E. GREENE,

T. D. EVERTS.

